The present invention relates to a cantilever type screen-printing machine with double platforms, more particularly to a screen-printing machine which possess a gear reducer motor with a hollow shaft to rotate a screw of a threaded screw unit and further drive a threaded rod to move upward and downward without rotation inside the hollow shaft thus make a transverse sliding assembly move vertically and synchronously with the threaded rod. Moreover, by a rectangular frame and two sets of horizontal micro adjustable chase clamping mechanism transversely fixed on the rectangular frame, the relative position between the chase and the print materials is adjusted directly. The upper and the lower platforms are driven and powered by two gear reducer motors and a homocentric coaxial-type driving mechanism respectively. By the simplified driving mechanism, the printing efficiency and productivity are enhanced.
According to description of prior arts, double-platform screen-printing machine already exists in the categories of cantilever type screen-printing. Each platform has its own gear mechanism so that both platforms can print and process top and bottom print matters reciprocally. Furthermore, double platforms has the function of printing and managing print materials simultaneously so as to reduce the idle time of changing printing materials. Therefore concerning printing speed and productivity, it is far more better than the printing machine with a single platform, but the designation can not be too complicated in order not to increase the machine cost and space occupation. Moreover, a conventional cantilever type double-platform screen-printing machine is less efficient than a single-platform screen-printing machine in precision control of the elevating mechanism of transverse sliding assembly's vertical shifting, or the relative position (such as x, y axis pair position or z axis's horizontal degree) between the chase and the printing materials.